Preparatory work to install average speed cameras on a notoriously dangerous road will begin next week.
The first phase of the programme will focus on the section of the A9 between Perth and Inverness, where cameras will be installed at 27 sites along the route.
Work to construct the necessary infrastructure for the cameras, including power connections, safety barriers, traffic signs and telecomms equipment, will begin on Monday and is set to last for 28 weeks.
Transport officials said lane closures and temporary traffic lights will be required in places as the work is carried out, but no significant delays are expected for motorists.
Chair of the A9 Safety Group Stewart Leggett said the cameras are part of a "comprehensive safety plan" for the road.
He said: "This work is the first stage of the installation of the cameras and we have worked hard to make sure that this is done with the minimum disruption for road users."
Most of the work will be carried out during the day between 8am and 5pm, but some work will take place overnight.
Eddie Ross, operating company representative for Bear Scotland, said: "Works have been carefully planned and we will endeavour to undertake them with as little disruption to road users as possible. We would ask for motorists to be patient during this time and their support whilst we undertake these important safety works is appreciated.
"Although delays are likely to be kept to a minimum, we would encourage road users to check with Traffic Scotland for the latest travel news before starting their journey."
Last week, the Transport Minister announced that work to convert part of the main route north to dual carriageway is being accelerated.
Keith Brown said three sections of the A9 between Perth and Inverness are now expected to be "shovel ready" for work to begin in 2017.
Most of the busy road is single carriageway, with the Scottish Government already having pledged to upgrade it to dual carriageway by 2025, with a £3 billion project to convert 80 miles of roadway.